Numerous useful features of portable computing devices rely on the ability of the devices to communicate information to and receive information from other computing devices. Wireless networking, in particular, provides portable computing devices with the ability to access information available on the Internet, send and receive messages to other users, send and receive a user's documents and information to and from other computing devices, and so on. Computing devices often use communication techniques such as cellular data, WiFi™, and the like to communicate with other devices. These communication techniques ordinarily require that an address, Uniform Resource Locator (URL), or other identifying information be known about the other device with which communication is to be established. These addresses are readily obtainable in some cases, e.g., for devices that have Domain Name Service (DNS) names, such as a web server accessible via the URL. However, there are many devices that do not have their own URLs or have URLs, but the URLs are not known to users who wish to access the devices. Even if a list of the available devices is available, there may be a large number of devices, and selecting the best one from a long list can be difficult. In other cases, devices do not have URLs, and are discovered using a protocol such as Bluetooth®.
For example, an Apple TV® device, available from Apple® Inc. of Cupertino, Calif., provides an interface from a computing device to a television. Mobile devices, such as smart phones, can use the Apple TV to display images on the television. However, establishing a connection between a mobile device and a wireless television devices (e.g., Apple TV or like), or wireless printer (e.g., using AirPrint® or the like) may require that the device user be registered in a certain way, which may not be the case in some environments such as classrooms. In another example, there are many devices, e.g., 20,000 or more, in an area such as an auditorium, arena, or the like. Identifying the device of a particular person can be difficult, because an attempt to connect to another device is likely to involve selecting the other device from a large list of devices.